Switching system and method for communicating information at a customer premises

ABSTRACT

A switching system ( 14 ) at a customer premises communicates information associated with one or more subscribers. The switching system ( 14 ) includes multiple subscriber line ports ( 17 ) for communicating xDSL signals with subscribers, the xDSL signals containing both data signals and POTS voice signals. A logical port ( 20 ) communicates data signals and packetized voice signals from the subscribers with a central office, the switching system ( 14 ) converting between the POTS voice signals of the subscriber lines ( 16 ) and the packetized voice signals of the logical port ( 20 ). A LAN port ( 21 ) communicates data signals with a server complex ( 23 ) using a LAN ( 22 ) to provide data services to the subscribers. The switching system ( 14 ) may include a switch ( 32 ) that receives voice signals on a first virtual circuit (VC), switches the voice signals out of the switching system ( 14 ) on the first VC, and also communicates received data signals for routing. A router ( 32 ) within the switching system ( 14 ) may receive the data signals from the switch ( 32 ) on a second VC, determine a third VC for the data signals, and route the data signals to the switch ( 32 ) on the third VC for communication out of the switching system ( 14 ) on the third VC.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/204,898, filed on May 17, 2000.

This application is related to:

-   -   U.S. application Ser. No. 09/___,___, filed Sep. 15, 2000 by        Brian W. Johnson, K. Arlan Harris, and Manlio D. Marquez, for a        System and Method for Prioritizing and Communicating Subscriber        Voice and Data Information; and    -   U.S. application Ser. No. 09/___,___, filed Sep. 15, 2000 by        Brian W. Johnson, for a System and Method for Communicating        Information Using Inverse Multiplex ATM (IMA) Functionality.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to the field of communications and inparticular to a switching system and method for communicatinginformation at a customer premises.

BACKGROUND OF THE INVENTION

Historically, voice, video, data, and other services have been providedseparately, using multiple facilities and separate wiring. As a result,communities requiring such services have usually faced relatively largeinitial expenses for implementing a system, subsequently increasingsystem capacity, and maintaining the system on an ongoing basis.Attempts to integrate such services to offset these inadequacies havetypically forced users in these communities to accept a number ofundesirable limitations, for example, limitations as to the generalityof data services available.

Communications needs continue to expand on a global scale. With thegrowing demand for communications, and despite the limitationsassociated with prior systems, there is a concurrent expansion in thedemand for audio, video, data, and other services provided to usercommunities. This is particularly true considering the recent rise inimportance of packet-based audio, video, data, and other communicationsthat rely on Asynchronous Transfer Mode (ATM), Internet Protocol (IP),Frame Relay (FR), and other packet-based protocols. For example, usersin a community such as an apartment complex or other shared tenantenvironment may have telephones, personal computers, facsimile machines,and other devices allowing them to interface to the public switchedtelephone network (PSTN), the Internet, and other suitable networks.Previous systems do not provide voice, video, data, and other servicesin an integrated manner using a system having relatively lowimplementation, scaling, and ongoing maintenance costs. As a result ofthese and other inadequacies, previous systems are often inadequate toaddress the current and future needs of many user communities.

SUMMARY OF THE INVENTION

According to the present invention, disadvantages and problemsassociated with previous switching systems and methods are substantiallyreduced or eliminated.

According to one embodiment of the present invention, a switching systemat a customer premises communicates information associated with one ormore subscribers. The switching system includes a switch that receivesvoice signals on a first virtual circuit (VC) and switches the voicesignals out of the switching system on the first VC. The switch alsocommunicates received data signals for routing. A router of theswitching system receives the data signals from the switch on a secondVC, determines a third VC for the data signals, and routes the datasignals to the switch on the third VC for communication out of theswitching system on the third VC.

In another embodiment of the present invention, a switching system at acustomer premises communicates information associated with one or moresubscribers. The switching system includes a local area network (LAN)port for communicating data signals with a server complex using a LAN toprovide one or more data services accessible to some or all subscribers,a logical port for communicating data signals and packetized voicesignals with a central office (CO), and multiple subscriber line portsfor communicating digital subscriber line (xDSL) signals withsubscribers. The switching system is able to communicate data signalsand plain old telephone service (POTS) voice signals between subscribersusing the subscriber line ports. The switching system also communicatesdata signals and POTS voice signals between subscribers and the CO usingthe subscriber line ports and the logical port, the switching systemconverting between the POTS voice signals of the subscriber lines andthe packetized voice signals of the logical port. The switching systemalso communicates data signals between subscribers and the servercomplex using the LAN port.

The present invention provides a number of important technicaladvantages over previous systems and methods. Unlike previous systems,the switching system of the present invention can be provisioned toinclude a single logical data link from the switching system to the COsite. This link bidirectionally carries data, packetized voice,packetized video, and any other appropriate packetized informationstreams. The switching system may provide POTS on multiple subscriberline ports, with built-in facilities to bidirectionally convert betweenthe analog POTS and packetized digital service to and from the CO. Itmay also provide suitable xDSL service over the POTS that is provided oneach subscriber line, with connectivity to an Internet service provider(ISP) for each of the subscriber lines. It may provide a built-in LANport (based on Ethernet or otherwise) and an associated switching (orrouting) bridge to support the creation of a LAN inclusive of thesubscriber line data channels and the LAN port. It may provide LANservice even for subscriber data connections using the Point to Point(PPP) protocol. The ability to provide these and other service optionsto multiple users within a community is an important technical advantageover prior systems.

Moreover, the switching system of the present invention is “stackable”using interconnecting links that permit multiple smaller devices tooperate as if they were a single larger device. The interconnecting“stack links” between devices can be modular and multiprotocol. Thesefeatures contribute to the enhanced scalability of the system and mayallow for economical incremental expansion beginning with a low cost ofentry version with a low port count. The switching system is moremanageable than prior systems, permitting both local and remoteconfiguration and monitoring. It may support single or multiple physicallinks to one or more COs, providing data link fault tolerant operation,higher bandwidth, and other important technical advantages. It may alsoprovide for distributed Inverse Multiplex ATM (IMA) operation usingthese CO links. The present invention allows various combinations ofthese and other services to be provided at lower total cost than withmultiple overlapping systems to provide such services piecemeal.

Systems and methods incorporating one or more of these or othertechnical advantages are well suited for user communities desiringintegrated voice, data, video, and other communications services. Othertechnical advantages are readily apparent to those skilled in the artfrom the following figures, descriptions, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the present invention andfurther features and advantages thereof, reference is now made to thefollowing description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 illustrates an exemplary system for communicating information ata customer premises;

FIG. 2 illustrates an exemplary network access switch;

FIG. 3 illustrates an exemplary stacked configuration of multiplenetwork access switches;

FIG. 4 illustrates an exemplary interface communicating local voice,local data, remote voice, and remote data signals;

FIG. 5 illustrates an exemplary prioritization scheme;

FIG. 6 illustrates exemplary network access switches supportingdistributed IMA functionality;

FIGS. 7A and 7B illustrate exemplary methods of communicating outgoingand incoming information, respectively, at a customer premises;

FIG. 8 illustrates an-exemplary method of communicating voice and datainformation associated with one or more subscribers;

FIGS. 9A and 9B illustrate two exemplary methods of prioritizing betweenvoice and data signals; and

FIG. 10 illustrates an exemplary method of communicating information ata customer premises or distributed central office using InverseMultiplex ATM (IMA) functionality.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an exemplary system 10 for communicating informationin a subscriber community to provide integrated audio, video, data, andother appropriate services to subscribers. The subscriber community mayinclude a business, apartment complex, retirement community,correctional facility, or any other customer premises in whichsubscribers share communications infrastructure and resources. Eachsubscriber in the served community has one or more associatedtelephones, personal computers, facsimile machines, or other devices tointerface with the public switched telephone network (PSTN) or othertelephone network, a local area network (LAN), metropolitan area network(MAN), wide area network (WAN), a global network such as the Internet,or any other suitable networks. Such devices may be referred tocollectively, where appropriate, as subscriber devices 12. Networkaccess switch 14 is coupled to subscriber devices 12 using subscriberlines 16 (and their subscriber line ports 17) and associated splitters18, which separate (or combine) the voice or other “narrowband” signalsfrom the video, data, or other “wideband” or “broadband” signals as theyare communicated to (or from) subscribers in the community. One or moresplitters 18 may be integral to or separate from network access switch14. Reference to voice signals, voice calls, voice traffic, or the likeis meant to encompass any suitable narrowband telephone signals, calls,or traffic. Analogously, reference to data signals, data calls, datatraffic, or the like is meant to encompass any appropriate video,multimedia, data, or other wideband or broadband signals, calls, ortraffic. In one embodiment, the subscriber lines 16 include asymmetricor other digital subscriber lines (xDSL) 16 and communicate xDSL signalsthat include, depending on traffic characteristics at the time, voicesignals, data signals, or both voice signals and data signals.

Network access switch 14 communicates voice and data signals between thesubscriber devices 12 and external networks using one or more links 20,which provide a single logical link between the network access switch 14and such external networks. The connection between network access switch14 and link 20 may be referred to as a logical port 19 of network accessswitch 14. In one embodiment, link 20 is a Ti or other WAN link thatsupports Asynchronous Transfer Mode (ATM), Internet Protocol (IP), FrameRelay (FR), or any other suitable packet-based WAN protocol. Althoughpackets (as opposed to frames) are primarily discussed, reference topackets is meant to include packets, frames, cells, and other suitableunits, as appropriate. Reference to frames or cells are to be similarlybroadly construed, as appropriate. Link 20 may include any wireline orwireless communications link providing suitable broadbandcharacteristics over a distance of interest, often the distance betweennetwork access switch 14 and a central office (CO) within the PSTN.Depending on the nature of link 20, voice signals received fromsubscribers may be packetized at network access switch 14 and thencommunicated over link 20 in association with data signals using voiceover ATM (VOA), voice over IP (VoIP), voice over FR (VoFR), voice overDSL (VoD), or other appropriate protocol. Voice signals destined forsubscribers may be depacketized at network access switch 14 andcommunicated over subscriber lines 16 to the subscribers in associationwith data signals using xDSL or another appropriate technique.

In addition to subscriber lines 16 and link 20 described above, networkaccess switch 14 also supports a LAN port 21 providing an interface toan Ethernet or other suitable LAN 22. Using LAN 22, network accessswitch 14 provides subscribers with access to a number of sharedresources, depending on the subscriber community and particular needs.In one embodiment, such resources may include a server complex 23 havinga maintenance or other request server 24 a, a game server 24 b, a videoon demand (VOD) or other video server 24 c, a webcam server 24 d, or anyother suitable servers 24 for providing desired functionality to usersin the community. Each server 24 may be coupled to one or morecorresponding peripheral devices. For example, webcam server 24d may becoupled to one or more still or video cameras providing continuous orperiodically updated images of selected areas of interest to thesubscriber community. In an apartment complex, as merely an example,such areas might include one or more entrance areas, laundry areas,mailbox areas, swimming pool areas, parking areas, and any othersuitable areas. The functionality provided using servers 24 generallydepends on the needs of community subscribers and management, the typesof services subscribers may be willing to pay for, and other appropriatefactors. Although link 20 is primarily described as coupling networkaccess switch 14 to a CO or other external network component, LAN port21 may be used instead of in addition to link 20 to provide suchconnectivity.

FIG. 2 illustrates an exemplary network access switch 14 that switchesand routes voice, video, data, and other suitable subscriber signalsusing switch/router 30 incorporating switch 32 and router 34. Switch 32and router 34 may be integral to or separate from one another and may belogically separate rather than physically separate entities. In general,switch 32 provide layer-2 switching functionality. Layer-2 switchingfunctionality is appropriate for certain types of signals, such as voicesignals, that are normally transported end-to-end by specific dedicatedATM switched virtual circuits (SVCs) or permanent virtual circuits(PVCs). Router 34 generally provides layer-3 routing functionality.Layer-3 functionality is appropriate for certain types of signals, suchas IP signals or FR signals, where the desired routing of the data mayvary from packet to packet and is determined by examining a portion ofthe content of each packet. In such cases, the function of the layer-3router is to examine individual frames being transported over inboundATM circuits, and to forward the frames via the appropriate outbound ATMcircuits that will take them to their intended destination.

In one embodiment, switch 32 and router 34 collectively provideswitching and routing functionality using a single switch matrix withinthe switch/router 30, although multiple switch matrices of switch/router30 may be used if appropriate. Switch 32 is preferably implemented usingone or more application specific integrated circuit (ASIC) devices,although switch 32 may be implemented in software running on a dedicatedor shared processor or in any other appropriate manner according toparticular needs. Similarly, router 34 may be implemented using one ormore ASIC devices, software, or any other suitable technique. Asdescribed more fully below with reference to FIGS. 6A and 6B, whereswitch/router 30 processes ATM signals, the switch 32 may supportInverse Multiplex ATM (IMA) functionality according to the presentinvention.

Voice processor 40 may be any commercial off-the-shelf or other voiceprocessor that provides analog to digital (A/D) and digital to analog(D/A) conversion, monitors various channels and the types of signalscommunicated on the channels, optionally provides voice compression,packetizes voice streams into ATM or other frames, depacketizes ATM orother frames into voice streams, and provides any other suitablefunctionality, in any appropriate combination and without limitation.xDSL processor 42 provides functionality associated with a traditionalDSL access multiplexer (D)SLAM). In general, xDSL processor 42 providesmodem functionality for encoding outgoing digital data signals into abroadband xDSL signal suitable for transmission over POTS, and fordecoding incoming broadband xDSL signals into digital data signals. Itprovides the data interface between the external subscriber lines andthe switch/router 30. It may also perform subscriber line managementfunctions such as training, signal quality monitoring, and connectionintegrity monitoring.

In one embodiment, outgoing voice or other “narrowband” analog telephonesignals received at network access switch 14 over subscriber line 16 areseparated from any data signals using a splitter 18, processed asappropriate using subscriber line interface card (SLIC) 38 and voiceprocessor 40, and received in packetized form at switch 32 for layer-2switching. Each voice call may have a dedicated virtual circuit (VC),such that all voice signals for a particular call are switched to andcommunicated on the same VC. Although a dedicated VC for each call isprimarily described, the present invention contemplates multiple callson the same VC, each having a dedicated channel. In the particularembodiment in which network access switch 14 processes voice signals asATM cells, switch 32 may use ATM adaptation layer type-2 (AAL-2)functionality, AAL type-1 (AAL-1) functionality, or both for switchingpacketized voice signals to ensure that ATM cells for a particular callare sent to the same VC. The packetized voice signals are communicatedfrom switch/router 30 on the assigned VC to a CO or other networkcomponent associated with link 20 or to a subscriber device 12associated with another subscriber line 16. Similarly, the incomingvoice signals from the CO or subscribers 16 are switched at networkaccess switch 14 using switch 32 and then communicated out to subscriberdevices 12 through voice processor 40, SLIC 38, splitter 18, andsubscriber lines 16.

In this embodiment, router 34 is not involved in routing or otherwiseprocessing packetized voice signals within switch/router 30. As aresult, there may be no need for private branch exchange (PBX) equipmentwithin system 10 to handle voice calls, which may reduce costsassociated with implementing and operating system 10. However, thepresent invention contemplates system 10 incorporating a suitable PBXfor handling voice calls, whether alone or in cooperation withswitch/router 30.

According to the present invention, data signals are treated somewhatdifferently than voice signals. In one embodiment, outgoing data signalsare separated from the voice signals using splitter 18, processed asappropriate using xDSL processor 42, and received at the switch/router30 in packetized form as ATM or other frames. Switch/router 30 usesswitch 32 to switch the ATM cells in layer-2 fashion and communicate thecells on a first VC to router 34. Router 34 determines in layer-3fashion a second VC for the cells and returns the cells to switch 32 onthe second VC. Finally, switch 32 switches the cells out ofswitch/router 30 on the designated second VC to the appropriatedestination. The destination may be a CO or other network componentassociated with link 20, a server 24 or other resource associated withLAN 22, or a subscriber device 12 associated with another subscriberline 16.

In one embodiment, layer-3 routing within switch/router 30 of packetizeddata signals may be managed and controlled using manager 44 inaccordance with particular traffic, security, revenue, and othersuitable considerations, providing an important technical advantage. Ingeneral, manager 44 measures utilization of data paths through networkaccess switch 14 and, in response, provides one or more routing rules torouter 34 for assignment of VCs and resulting routing of data signalsthrough network access switch 14. Manager 44 may also controldifferential billing of a subscriber relative to other subscribers basedon its measurement of the nature and quantity of data traffic associatedwith the subscriber at a particular time or during a particularinterval. For example, when the bandwidth through network access switch14 is scarce, manager 44 may bill a subscriber who is communicating orreceiving a relatively large quantity of data traffic more per volume ofdata traffic than a subscriber who is communicating or receiving asmaller quantity of data traffic. Manager 44 may also monitor IPaddresses associated with data signals subscribers communicate andreceive, communicating this information to an appropriate server 24using LAN 22. To improve security or for any other suitable reason,manager 44 may have a dedicated VC.

Analogously, incoming packetized data signals are received atswitch/router 30 and switched, in layer-2 fashion at switch 32, torouter 34 on a first VC. The router 34 determines in layer-3 fashion asecond VC for the cells and returns these cells to switch 32 on thedesignated second VC. Finally, the switch 32 switches the cells out ofthe switch/router 30 on the second VC to a subscriber device 12 usingxDSL processor 42, splitter 18, and a suitable subscriber line 16. Inthe particular embodiment in which network access switch 14 processesthe data signals as ATM cells, appropriate ATM adaptation layer type-5(AAL-5) functionality may be used within network access switch 14. Forexample, link 20 maybe an IP link to the Internet, and protocolconverter 46 may convert the IP packets received on link 20 to ATMframes, using AAL-5 techniques or otherwise, for communication toswitch/router 30.

Thus, according to the present invention, network access switch 14provides a forwarding mechanism for data signals (using switch 32 androuter 34) that overlays a forwarding mechanism for voice signals (usingswitch 32 only) using a single switch matrix. As discussed above, amongother benefits, the separate treatment of data signals using router 34enables enhanced management and control with respect to these datasignals according to the operation of manager 44.

In one embodiment, since subscriber devices 12 typically handle only asingle VC, switch/router 30 preferably combines multiple incoming ATMstreams on a single VC for communication to a subscriber device 12.Switch/router 30 collects the ATM cells corresponding to a particularATM frame, which may arrive at switch/router 30 on a number of differentVCs, interleaved with other frames arriving on the VCs, until all thecells for that frame have been received within switch/router 30. Thecells for that frame are then assembled and the complete frame isforwarded for communication to subscriber device 12 on a single VC. Foran outgoing ATM stream that switch/router 30 receives from subscriberdevice 12, switch/router 30 analogously communicates cells for a singleframe to their destination on what may include multiple VCs.

Router 34 preferably multiplexes ATM cells from different VCs onto asingle VC while preserving AAL-5 frame boundary integrity and ATM cellsequencing, possibly with assistance from switch 32. In a particularembodiment, router 34 maintains a cell queue for each inbound VC,preferably large enough to handle cells for several maximum size frames.Router 34 maintains a set of cell flags allowing it to keep track ofcells constituting frame boundaries (indicating the first, last, or bothfirst and last cells in each frame). Router 34 performs routing for anoutbound VC in response to the last cell of a frame being forwarded fromswitch 32 to router 34, router 34 selecting from among the availableinbound VCs for which the first cell of a frame destined for theoutbound VC is available. This selection may occur according to suchthings as priority, relative link speeds of the inbound and outboundports, “age” of the frames available to be forwarded, or any othersuitable criteria In one embodiment, to reduce interaction betweenmultiple traffic types, the cell queues may be used only for the AAL-5streams requiring this processing. For example and not by way oflimitation, AAL type-0 (AAL-0) and AAL-2 cells might be forwardedimmediately according to typical ATM mechanisms (being switched inlayer-2 fashion by switch 32), since ATM cells can be switched in eitherlayer-2 or layer-3 fashion. Although this processing is describedprimarily as being the task of router 34, switch 32 may cooperate withrouter 34 as appropriate to achieve the desired results. For example,router 34 may operate essentially independently of and parallel toswitch 32 or may instead operate as a policy control mechanism that ismore closely integrated with switch 32 and guides its operation.

In another embodiment more preferably suited to a software (as opposedto a hardware) implementation of this processing, the AAL-5 frames maybe converted to memory-buffered frames using a segmentation andreassembly (SAR) mechanism. The frames may then be “switched” and passedback through the same or a different SAR mechanism to convert the framesback to AAL-5 format. Other appropriate techniques for ATM cellsequencing may be employed without departing from the intended scope ofthe present invention. Additionally, as described more fully below withreference to FIGS. 6A and 6B, suitable IMA functionality associated withswitch/router 30 may participate in ATM cell sequencing.

In one embodiment, network access switch 14 may provide subscribers withsimultaneous connectivity to an external Internet service provider (ISP)and one or more private local servers 24 (visible only to thesesubscribers, who are separated from the Internet by network accessswitch 14). In prior systems, if a computer communicates with an ISP orother external device using only the Point to Point (PPP) protocol, theneither there is no connectivity to local devices or the local devicesmust be publicly visible on the Internet. Sometimes, neither of theseconditions is desirable. According to the present invention, networkaccess switch 14 provides subscribers visibility to private localdevices (servers 24), providing associated LAN services using the PPPprotocol, while simultaneously providing the subscribers with Internetaccess through connectivity to an external ISP. The PPP link may be aserial link (through a POTS or xDSL modem), PPP over ATM (e.g., overAAL-5), PPPoE (PPP over Ethernet), or any other suitable PPP connectionmethodology. The link may be configurable to operate in a conventionalbridged mode, a conventional routed mode, or in PPP mode, withswitch/router 30 automatically determining when PPP mode is being used.

In one embodiment, the switch/router 30 provides a switching bridgethrough which PPP streams may pass on their path from subscriber devices12 (such as personal computers) to an external ISP. Switch/router 30 isalso coupled to one or more servers 24. Switch/router 30 examines thecontents of the PPP stream, selectively separates certain packets out ofthe PPP stream when it detects packets that are intended for a server24, and forwards them only to the intended server 24. Similarly, packetsarriving at switch/router 30 from a server 24 are formatted into the PPPformat and gracefully inserted into the PPP stream sent back to thesubscriber device 12. This is preferably done such that communicationsto and from the ISP are maintained for the packets exchanged betweensubscriber device 12 and Internet destinations reached through the ISP.In one embodiment, switch/router 30 makes these routing decisions usinglayer 3 addressing information (e.g., IP addresses) embedded in thepacket headers, although any appropriate information in the packet maybe used.

Switch/router 30 may monitor and intervene in the PPP negotiationprocess to influence the negotiation (by forcing specified choices, suchas “no compression”), to know where in the PPP stream to look for thedecision information, and to know the relevant identificationinformation (e.g., the IP address) of the subscriber device 12. If thePPP stream is compressed, it may be necessary for switch/router 30 todecompress the PPP stream to make forwarding decisions. Alternatively,compressed PPP streams could simply be passed on without examination.

According to the present invention, network access switch 14 allows thelocal web servers 24 to be visible to subscriber devices 12, but notvisible to external Internet users, even when subscriber devices 12 arenetwork connected using a single network connection to an external ISPusing the PPP protocol. For example only and without limitation, thisfeature may be particularly desirable for an apartment complex, whereeach resident may be provided a single (physical) network connectionconfigured as a PPP link to an external ISP through network accessswitch 14 located on the premises, and where the apartment complex alsoprovides, for example, web cameras at strategic sites associated withthe complex (e.g., front gate, front door, playground, swimming pool,laundry room, or any other suitable location).

FIG. 3 illustrates an exemplary stacked configuration of multiplenetwork access switches 14 coupled to one another using stack links 50.Although an exemplary “daisy chain” topology is shown, the presentinvention contemplates any number of network access switches 14 coupledto one another using a ring, mesh, or any other appropriate topology.Each network access switch 14 handles associated local voice signals 52communicated with voice processor 40 and associated local data signals54 communicated with xDSL processor 42 and LAN 22. Local voice signals52 and local data signals 54 for a network access switch 14 may becommunicated to other network access switches 14 using interface 56 andappropriate stack links 50. As an example, network access switch 14 amay communicate its local voice signals 52 and local data signals 54using its interface 56 to network access switch 14 b, network accessswitch 14b may communicate its local voice signals 52 and local datasignals 54 using its interface 56 to either or both network accessswitches 14 a and 14 c, and so on. Stack links 50 may each include oneor more interconnect ports, such that any desired number of pathsbetween devices may be supported with no shared points of failure otherthan the end devices themselves.

Since each network access switch 14 may not support its own link 20,local voice signals 52 and local data signals 54 destined for link 20 orsubscriber lines 16 associated with another network access switch 14, orincoming voice and data signals received on link 20, may need totraverse multiple stack links 50 to reach its intended destination. Thestacked configuration of multiple network access switches 14 coupledusing stack links 50 may provide relatively inexpensive incrementalgrowth, fewer single points of failure and thus increased faulttolerance, and other benefits. For example, for fault tolerance, networkaccess switches 14 may be coupled in the daisy chain configurationshown, such that each network access switch 14 is coupled to twoadjacent network access switches 14 and signals may be communicatedbetween any of the non-failing network access switches 14 (assuming onlyone network access switch 14 in the chain has failed). Since eachnetwork access switch 14 supports a specified number of subscriber lines16, incremental growth may be achieved by adding another network accessswitch 14 and associated stack links 50 to the configuration, ratherthan replacing a network access switch 14 with another network accessswitch 14 having a greater capacity.

In one embodiment,.only one network access switch 14 among thecollection of network access switches 14 supports a link 20, for costsavings, reduced complexity, or any other suitable reason. However, thepresent invention contemplates more than one link 20 for a collection ofnetwork access switches, for example, to provide redundancy andincreased fault tolerance. In this case, if one of multiple links 20fails, the capacity of system 10 may be decreased, yet communications toexternal networks on other links 20 will still be available. One or morelinks 20 may be associated with a collection of multiple network accessswitches 14 in any appropriate manner. Each stack link 50 preferably hasat least the same bandwidth capacity as link 20, such that the signalsreceived on link 20 are not undesirably slowed or otherwise impeded asthey travel to their destinations, possibly through multiple stack links50, even when traffic associated with one or more network accessswitches 14 is unusually heavy at that time. Similarly, switch/router 30of each network access switch 14 is preferably able to process themaximum traffic associated with system 10, such that the overall trafficflow is not unduly slowed or otherwise impeded within a particularnetwork access switch 14, even when the traffic associated with thatnetwork access switch 14 is unusually heavy at that time.

According to the present invention, interface 56 within each networkaccess switch 14 may implement an intelligent prioritization scheme toimprove the efficient communication of voice and data signals throughsystem 10. In this regard, at least two classes of information may bedefined according to its time-sensitivity. Referring to FIG. 4, in oneembodiment the first class of relatively time-sensitive informationincludes both remote voice signals 60 (originating across stack link 50)and local voice signals 52. Relatively time-insensitive informationincludes both remote data signals 62 (originating across stack link 50)and local data signals 54 (originating within network access switch 14of interface 56). Interface 56 attempts to maintain absolute priority ofvoice signals over data signals. These classifications reflect the factthat voice traffic is generally subject to an end-to-end delay budget,making it preferable to add as little delay as possible in passing voicesignals between network access switches 14 using one or more stack links50. In contrast, data traffic is generally less delay sensitive and maytherefore be placed behind voice traffic in terms of relative priority.Although remote signals are shown entering interface 56 in a particulardirection from adjacent network access switch 14, and combined remoteand local signals are shown leaving interface 56 in a particulardirection to another adjacent network access switch 14, this descriptionapplies similarly to all signals entering or leaving interface 56,regardless of direction or the one or more other network access switches14 involved.

Within each of these two classes, interface 56 attempts to preserve thepriority based on origination across at least a portion, and preferablythe entire, stack of network access switches 14. This preferablyminimizes variations in delivery latency, particularly the latencyassociated with traversing one or more stack links 50. In addition, itis generally preferably for the system not to favor one network accessswitch 14 within the stack, the network access switch 14 closest to link20 for example, relative to the other network access switches 14. FIG. 5illustrates an exemplary prioritization scheme that is implementedwithin a signal scheduler or other priority device 70 within interface56 or otherwise associated with network access switch 14. In oneembodiment, remote voice signals 60 are given highest priority, localvoice signals 52 are given second highest priority, remote data signals62 are given third highest priority, and local data signals 54 are givenfourth highest priority. Additional sub-classes and priority levels forvoice signals, data signals, or both voice and data signals may bedefined. It is assumed that link 20 has sufficient bandwidth to handleall voice signals 52 and 60 without undue queuing delay, although thebandwidth of link 20 may be insufficient to handle all data signals 54and 62 without possibly significant such delay.

These relative priorities may be altered, if suitable, without departingfrom the intended scope of the present invention. In one embodiment,timestamps (which are synchronized across network access switches 14 inthe stack) may be inserted into the traffic upon or in association withits receipt at network access switch 14, its processing within networkaccess switch 14, or in any other suitable manner. If priority device 70is prepared to communicate signals and voice signals 52, 60, or both 52and 60 are present, priority device 70 may use the timestamps to selectthe “oldest” voice signals 52 or 60 for communication, neither theremote voice signals 60 nor the local voice signals 52 having priorityover one another. Alternatively, such as where timestamps areimpractical or otherwise undesirable, priority device 70 may apply thedescribed four-level priority scheme to selectively communicate remotevoice signals 60 before local voice signals 52. If no voice traffic ispresent, but data traffic is present, then priority device 70 may usethe timestamps to select the oldest data signals 54 or 62 forcommunication, neither remote data signals 62 nor local data signals 54having priority over one another. Alternatively, such as wheretimestamps are impractical or otherwise undesirable, priority device 70may apply the described four-level priority scheme to selectivelycommunicate remote data signals 62 before local data signals 54. If atany point only one type of signals are present, priority device 70 maysimply select and communicate those signals (preferably oldest signalsfirst), with or without regard to the priority scheme.

In addition, the prioritization scheme may use a sub-algorithm to shapedata traffic according to factors such as which traffic generates themost revenue for the system operator, whether traffic is associated witha user who has paid a premium or more than other users, or any othersuitable factors. For example, a non-premium user may have paid for useof 1 Mbps of pre-allocated bandwidth, while a premium user may have paida greater amount for use of 2 Mbps. As a result, local data signals 54associated with the premium user may be given a higher priority thanremote data signals 62 associated with the non-premium user. Such asub-algorithm may select among remote data signals 62 and local datasignals 54 according to recent per-port traffic statistics relative toconfigured per-port bandwidth allowances. For example, interface 56 mayexamine recent traffic statistics, scale local data signals 54 accordingto what associated users have paid, and use an appropriate share ofavailable bandwidth to communicate local data signals 54. Other networkaccess switches 14 may similarly be trusted to appropriately scale theirlocal data signals 54 in a similar manner.

In one embodiment, the described prioritization schemes allowpreservation of quality of service (QoS) for various classes of datatraffic in an environment, in this case a stacked configuration ofmultiple network access switches 14, that does not formally support QoS.These schemes also support concurrent voice and data traffic. Althoughspecific schemes are described, the present invention contemplatesprioritizing among remote voice signals 60, local voice signals 52,remote data signals 62, and local data signals 54 in any suitable mannerto optimize the flow of traffic into, within, and out of one or morestacked network access switches 14. One or more prioritization schemesmay be implemented at each interface 56 for each cell, frame, packet, orother suitable signal unit as it travels between the network accessswitches 14 using one or more stack links 50. Alternatively, one or moreprioritization schemes may be wholly or partially distributed amongmultiple interfaces 56, as appropriate.

For an embodiment utilizing ATM as the transport mechanism, theprioritization schemes discussed may either supplement or replace, inwhole or in part, the normal ATM QoS mechanisms. This is particularlysignificant when the stack links 50 are of relatively low bandwidth, asmight be the case with copper connections, and the offered data trafficload greatly exceeds the stack link 50 bandwidth capability.

As described above, multiple links 20 may be coupled to an associationof one or more network access switches 14 to increase fault tolerance orfor any other suitable reason. When multiple physical communicationlinks-are coupled between a CO and a customer premises equipment (CPE)device, such as when multiple links 20 are used, it is generallydesirable to use all of the “up” links from the CO to the CPE device toobtain maximum possible bandwidth. For ATM networks, the standard ~IAprotocol may be sufficient to provide this result. However, IMA assumesthat all such links terminate on a single device that performs any ATMcell sequencing necessary to restore proper cell sequence, which mayhave been disturbed as a result of differential latency between themultiple links. If the CPE device is instead distributed, as is the casewhen multiple network access switches 14 are stacked and are coupledusing stack links 50, then this is plainly not the case.

FIGS. 6A and 6B illustrate an exemplary configuration of multiplestacked network access switches 14 collectively associated with at leasttwo links 20 a and 20 b. Links 20 a and 20 b may be referred to in thesingular as link 20 and in the plural as links 20. Those skilled in theart appreciate that any number of links 20 may be associated withnetwork access switches 14 without departing from the intended scope ofthe present invention. In general, each VC must be statically allocatedamong links 20 a and 20 b. For example, a particular VC may be entirelyon link 20 a, switching to link 20 b only in response to failure of link20 a. Similarly, the VC may be entirely on link 20 b, switching to link20 a only in response to failure of link 20 b. Alternatively, the VC mayinstead be partitioned in some suitable manner between links 20 a and 20b. However, regardless of the exact manner in which the VC is allocated,that allocation is generally static for the duration of the VC andcannot be dynamically modified

According to the present invention, rather than provide full IMAfunctionality in a single network access switch 14 as the IMA standardcontemplates, IMA functionality may be distributed among multiplenetwork access switches 14 as a component of switch/routers 30 withinthe network access switches 14. In one embodiment, for a particular VC,all network access switches 14 direct incoming ATM signals for that VCto an appropriate destination network access switch 14 for IMAprocessing. For example, as shown in FIG. 6A, VCs 82 a and 82 b may eachbe completely allocated to links 20 a and 20 b, respectively, while VC82 c may be partitioned among links 20 a and 20 b in a suitable manner.VCs 82 a, 82 b, and 82 c may be referred to in the singular as VC 82 andin the plural as VCs 82. IMA functionality 80 a, 80 b, and 80 c may bereferred to either in the singular or in the plural as IMA functionality80.

As shown in FIG. 6B, regardless of associations between VCs 82 and links20, VCs 82 are each directed to the appropriate destination networkaccess switch 14 for IMA processing using IMA functionality 80 of theassociated switch/router 30. For example, in the illustrated embodiment,all ATM signals on VC 82 a are directed for processing by IMAfunctionality 80 a, all signals on VC 82 b are directed for processingby IMA functionality 80 b, and all the signals on VC 82 c are directedfor processing by IMA functionality 80 c. ATM cell sequencing, accordingto the IMA protocol, is performed at each network access switch 14 forcorresponding VCs 82, independent of the ATM cells directed to the othernetwork access switches 14. The outgoing ATM cells from each networkaccess switch 14 are similarly directed to the appropriate links 20 forcommunication to the CO, which is assumed to support IMA processing ofATM cells receiving from the stack of network access switches 14.

Providing distributed IMA functionality 80 according to the presentinvention provides a number of important technical advantages. Analternative solution might be to provide IMA functionality at only asingle network access switch 14 within a stack. Although this mayprovide cost benefits relative to providing complete or partial IMAfunctionality in multiple network access switches 14, doing so wouldrequire use of valuable bandwidth on stack links 50 to communicate theincoming ATM signals from the network access switch 14 on which theywere received to the network access switch 14 supporting the IMAfunctionality. Doing so would also result in increased delay, since theATM signals might in general need to traverse the same one or more stacklinks 50 multiple times, depending on the relationship between thenetwork access switch 14 on which incoming ATM signals were received,the network access switch 14 supporting the IMA functionality, and thedestination network access switch 14. The distribution of IMAfunctionality 80 according to the present invention reduces oreliminates these problems.

Because the IMA protocol is used, if one of N links 20 fails, all theincoming ATM traffic becomes present on the remaining N−1 links 20.However, the present invention additionally ensures that if one networkaccess switch 14 fails, only IMA functionality 80 associated with thefailed network access switch 14 may be lost, since IMA functionality 80is distributed among at least some and preferably all of the othernetwork access switches 14. In one embodiment, failure of a networkaccess switch 14 may result in loss of associated link 20, subscriberlines 16, switch/router 30 including IMA functionality 80, and one ormore stack links 50. Therefore, in one embodiment, network accessswitches 14 are preferably coupled in a daisy chain, ring, mesh, orother suitable topology in which each network access switch 14 iscoupled to at least two adjacent network access switches 14 and trafficmay be communicated between any two non-failing network access switches14 (assuming only one network access switch 14 in the configuration hasfailed). Although a distributed CPE end is described, the presentinvention contemplates distributing IMA functionality 80 to supportterminating links 20 on multiple devices within a distributed CO endinstead of or in addition to a distributed CPE end.

FIGS. 7A and 7B illustrate exemplary methods of communicating outgoingand incoming information, respectively, at a customer premises. Althoughthe methods of FIGS. 7A and 7B are described primarily with respect toATM frames and cells, the present invention contemplates the voice anddata signals being formatted in any appropriate manner. Referring toFIG. 7A for outgoing traffic, the method begins at step 100, wheresplitter 18 separates outgoing data signals from outgoing voice signals.The separated voice signals are processed as appropriate using SLIC 38and voice processor 40 at step 102 and received in packetized form atswitch/router 30 at step 104. Switch 32 switches the associated cells inlayer-2 fashion at step 106, communicates the switched cells out ofswitch/router 30 on the VC dedicated to the particular call at step 108,and the method ends. In the particular embodiment in which networkaccess switch 14 processes voice signals as ATM cells, switch 32 may useAAL-2 functionality, AAL-1 functionality or both for switchingpacketized voice signals to ensure that ATM cells for a particular callare sent to the same dedicated VC.

As discussed above, the separated outgoing data signals are treatedsomewhat differently than the outgoing voice signals. After the datasignals are separated from the voice signals at step 100, xDSL processor40 processes the data signals as appropriate at step 110 andswitch/router 30 receives the data signals in packetized form at step112. Switch 32 switches the associated cells containing the data signalsin layer-2 fashion at step 114 and, at step 116, communicates theswitched cells on a first VC to router 34. Router 34 determines inlayer-3 fashion a second VC for the cells at step 118 and returns thecells to switch 32 on the second VC at step 120. In one embodiment, asdescribed above, layer-3 routing of data signals may be managed andcontrolled using manager 44 according to particular traffic, security,revenue, or any other suitable considerations. Finally, at step 122,switch 32 switches the cells out of switch/router 30 on the second VC tothe appropriate destination, and the method ends. The destination may bea CO or other network component associated with link 20, a server 24 orother resource associated with LAN 22, or a subscriber device 12associated with another subscriber line 16.

Referring to FIG. 7B for incoming traffic, the method begins at step150, where protocol converter 46 may convert incoming packetizedsignals, such as IP packets received on link 20, to ATM frames.Switch/router 30 receives the incoming ATM frames at step 152 and switch32 switches the corresponding ATM cells in layer-2 fashion at step 154.If the cells represent voice signals at step 156, switch 32 communicatesthe switched cells on the assigned VC dedicated to the particular callat step 158, voice processor 40 and SLIC 38 process the voice signals asappropriate at step 160, and the method proceeds to step 172.Alternatively, if the cells represent data signals at step 156, switch32 communicates the switched cells on a first VC to router 34 at step162. At step 164, router 34 determines in layer-3 fashion a second VCfor the cells and, at step 166, returns the cells to switch 32 on thesecond VC. Switch 32 then switches the cells out of switch/router 30 onthe second VC at step 168 and xDSL processor 42 processes the datasignals as appropriate at step 170. At step 172, splitter 18 combinesthe data signals (received from xDSL processor 42) with the voicesignals (received from SLIC 38) for communication to subscriber devices12, and the method ends.

FIG. 8 illustrates an exemplary method of communicating voice and datainformation associated with one or more subscribers. The method beginsat step 200, where a first network access switch 14 may associatetimestamps (which are preferably synchronized across network accessswitches 14 in the stack) with remote voice signals 60 and remote datasignals 62 upon or in association with their receipt at first networkaccess switch 14, during their processing within first network accessswitch 14, or in any other suitable manner. The present inventioncontemplates timestamps being associated with the traffic before itsreceipt at first network access switch 14. At step 202, first networkaccess switch 14 communicates remote voice signals 60 and remote datasignals 62 to a second network access switch 14 using an appropriatestack link 50. Second network access switch 14 receives the remote voicesignals 60 and remote data signals 62 at step 204 using interface 56. Atstep 206, second network access switch 14 receives local voice signals52 and local data signals 54 from subscribers associated with secondnetwork access switch 14 using corresponding subscriber line ports 17.At step 208, second network access switch 14 may associate timestampswith local voice signals 52 and local data signals 54 upon or inassociation with their receipt at second network access switch 14,during their processing within second network access switch 14, or inany other suitable manner. The present invention contemplates timestampsbeing associated with the traffic before its receipt at first networkaccess switch 14. As described above, timestamps associated with thevarious voice and data traffic processed at second network access switch14 may be used in determining the relative priority of such traffic forsubsequent communication from the second network access switch 14.

At step 210, second network access switch 14 communicates the localvoice signals 52 and local data signals 54 from the subscriber lineports 17 on which they were received to interface 56. Second networkaccess switch 14 applies one or more priority schemes at step 212 usingpriority device 70 within interface 56. For example, as described morefully above with reference to FIG. 3 and below with reference to FIGS.9A and 9B, the relative priorities among local voice signals 52, localdata signals 54, remote voice signals 60, and remote data signals 62 maybe determined according to the described four-level priority scheme,timestamps associated with the signals (thereby indicating the “oldest”signals of each type), a sub-algorithm for shaping data trafficaccording to revenue, bandwidth, or any other suitable considerations,or any other appropriate technique, singly or in any combination. Atstep 214, second network access switch 14 communicates the signals inaccordance with the selected priority scheme, and the method ends.

FIGS. 9A and 9B illustrate two exemplary methods of prioritizing betweentypes of voice and data traffic for communication from network accessswitch 14. The method illustrated in FIG. 9A relies in part upontimestamps associated with the traffic to be prioritized. The methodbegins at step 220, where if local voice signals 52, remote voicesignals 60, or both local signals 52 and 60 are present, network accessswitch 14 communicates the oldest available voice signals 52 or 60 atstep 222 based on timestamps associated with the voice signals 52 and60. In this embodiment, neither remote voice signals 60 nor local voicesignals 52 have priority over one another. After communicating theoldest available voice signals 52 or 60 at step 222, the method returnsto step 220 and repeats until no voice signals 52 or 60 are present, inwhich case the method proceeds to step 224. If local data signals 54,remote data signals 62, or both data signals 54 and 62 are present atstep 224, network access switch 14 communicates the oldest availabledata signals 54 or 62 at step 226 based on timestamps associated withthe data signals 54 and 62. In this embodiment, neither remote datasignals 62 nor local data signals 54 have priority over one another.After communicating the oldest available data signals 54 or 62, themethod returns to step 224 and repeats until no data signals 54 or 62are present, in which case the method ends.

FIG. 9B illustrates prioritization according to the four-level priorityscheme described above, although any suitable priority scheme may beused without departing from the intended scope of the present invention.In addition, although the method is described irrespective of timestampsor any determination of the relative “age” of the traffic to becommunicated, the present invention contemplates suitably combining themethods of FIGS. 9A and 9B in whole or in part, if appropriate,according to particular needs. For example, as described above, remotevoice signals 60 may have higher priority than local voice signals 52,while remote data signals 62 and local data signals 54 may have the samepriority and be communicated oldest signals first. The method begins atstep 240, where if remote voice signals 60 are present, network accessswitch 14 selectively communicates the available remote voice signals 60at step 242. The method returns to step 240 and repeats until no moreremote voice signals 60 are present, in which case the method proceedsto step 244. If local voice signals 52 are present at step 244, networkaccess switch 14 selectively communicates the local voice signals 52 atstep 246. The method then returns to step 244 and repeats until no localvoice signals 52 are present, in which case the method proceeds to step248.

If remote data signals 62 are present at step 248, network access switch14 selectively communicates the remote data signals 62 at step 250. Themethod then returns to step 248 and repeats until no remote data signals62 are present, in which case the method proceeds to step 252. If localdata signals 54 are present at step 252, network access switch 14selectively communicates the local data signals 54 at step 254. Themethod then returns to step 252 and repeats until no local data signals54 are present, in which case the method ends. Although the method isdescribed as proceeding forward in time between its steps, the decisionflow represented in FIG. 9B may occur at substantially one time or themethod may at any time return to a previous step such that the highestpriority traffic available is always communicated first.

FIG. 10 illustrates an exemplary method of communicating information ata customer premises or distributed CO using Inverse Multiplex ATM (1MA)functionality. The method begins at step 300, where a first networkaccess switch 14 receives first incoming ATM traffic. At step 302, firstnetwork access switch 14 determines that at least a portion of the firstATM traffic is associated with a particular VC. At step 304, firstnetwork access switch 14 directs that portion of the first ATM trafficfor the particular VC to a particular destination network access switch14 for IMA processing. A second network access switch 14 receives secondincoming ATM traffic at step 306 and, at step 308, determines that atleast a portion of the second ATM traffic is associated with theparticular VC. At step 310, the second network access switch 14 directsthat portion of the second ATM traffic for the particular VC to theparticular destination network access switch 14 for IMA processing. Atstep 312, the particular destination network access switch 14 receivesthe portions of the first and second ATM traffic for the particular VC.At step 314, IMA functionality at the particular destination networkaccess switch 14 performs cell sequencing for the received portions ofthe first and second ATM traffic for the particular VC, and the methodends. Although the method is described for purposes of explanation asinvolving an exemplary configuration of at least three network accessswitches 14, the present invention contemplates the method beingperformed with respect to any appropriate configuration of two or morenetwork access switches 14, at least one of which first determines thatcertain ATM traffic is associated with a VC having another networkaccess switch 14 as its destination, and then directs that ATM trafficto the destination network access switch 14 for cell sequencing withother ATM traffic for that VC.

Although the present invention has been described with severalembodiments, a plethora of changes, substitutions, variations,alterations, and modifications may be suggested to one skilled in theart, and it is intended that the invention encompass all such changes,substitutions, variations, alterations, and modifications as fall withinthe spirit and scope of the appended claims.

1. A switching system at a customer premises for communicating voice anddata information associated with one or more subscribers, comprising: alocal area network (LAN) port for communicating data signals with aserver complex using a LAN to provide one or more data servicesaccessible to some or all subscribers; a logical port for communicatingdata signals and packetized voice signals with a central office (CO); aplurality of subscriber line ports for communicating digital subscriberline (xDSL) signals with the subscribers; the switching system operableto: communicate data signals and plain old telephone service (POTS)voice signals between subscribers using the subscriber line ports;communicate data signals and POTS voice signals between subscribers andthe CO using the subscriber line ports and the logical port, theswitching system operable to convert between the POTS voice signals ofthe subscriber lines and the packetized voice signals of the logicalport; and communicate data signals between subscribers and the servercomplex using the LAN port.
 2. The switching system of claim 1, whereinthe server complex comprises one or more servers selected from the groupconsisting of: a subscriber request server; a game server; a video ondemand (VOD) server; and a webcam server.
 3. The switching system ofClam 1, wherein the logical port comprises one or more physical portseach coupled to a corresponding physical communications link between theswitching system and the CO.
 4. The switching system of claim 3, whereineach link comprises a wide area network (WAN) link supporting a protocolselected from the group consisting of: Asynchronous Transfer Mode (ATM);Internet Protocol (IP); and Frame Relay (FR).
 5. The switching system ofclaim 1, wherein the xDSL signals comprise at least asymmetrical DSL(ADSL) signals.
 6. The switching system of claim 1, further comprising:a splitter operable to separate voice signals received at the subscriberline ports from data signals received at the subscriber line ports, thesplitter being further operable to communicate the separated voice anddata signals; a voice processor operable to receive the separated voicesignals from the splitter, process the voice signals, and communicatethe processed voice signals for routing within the switching system; andan xDSL processor operable to receive the separated data signals fromthe splitter process the data signals, and communicate the processeddata for routing within the switching system.
 7. The switching system ofclaim 1, wherein the switching system is further operable to provideconnectivity to an Internet service provider (ISP) for each subscriberline port.
 8. (Canceled)
 9. The switching system of claim 8, furthercomprising a manager operable to communicate one or more routing rulesto the router for routing the data signals.
 10. The switching system ofclaim 9, wherein the routing rules reflect one or more considerationsselected from the group consisting of: traffic considerations; securityconsiderations; and revenue considerations.
 11. (Canceled)
 12. Theswitching system of claim 11, further comprising a manager operable tocommunicate one or more routing rules to the router for determination ofthe third VC, wherein the routing rules reflect one or moreconsideration selected from the group consisting of: trafficconsiderations; security considerations; and revenue considerations. 13.The switching system of claim 11, wherein: the voice signals and thedata signals are handed within the switch/router as asynchronoustransfer mode (ATM) frames; the switch is operable to use either ATMadaptation layer type-2 (AAL-2) or ATM adaptation layer type-1 (AAL-1)functionality to ensure that the voice signals are switched to the firstVC on which they are received; and the router is operable to use ATMadaptation layer type-5 (AAL-5) functionality to route the data signalsfrom the second VC to the third VC.
 14. The switching system of claim11, wherein the switch/router comprises a single switch matrix operableto implement the switching and routing.
 15. The switching system ofclaim 1, further comprising an interface for coupling to one or moreother switching systems at the customer premises using one or more stacklinks, such that the switching systems are operable to function as asingle logical unit communicate information between the subscribers, theCO, and the server complex.
 16. A switching system at a customerpremises for communicating voice and data information associated withone or more subscribers, comprising: a switch operable to receive voicesignals on a first virtual circuit (VC) and to switch the voice signalsout of the switching system on the first VC, the switch further operableto communicate received data signals for routing; and a router operableto receive the data signals from the switch on a second VC, to determinea third VC for the data signals, and to route the data signals to theswitch on the third VC for communication out of the switching system onthe third VC.
 17. (Canceled)
 18. The switching system of claim 16,wherein a single switch matrix of the switching system is operable toimplement the switching and routing.
 19. A switching system of claim 16,further comprising a manager operable to communicate one or more routingrules to the router for routing of the data signals.
 20. The switchingsystem of claim 19, wherein the routing rules reflect one or moreconsideration selected from the group consisting of: trafficconsiderations; security considerations; and revenue considerations. 21.The switching system of claim 16, further comprising: a splitteroperable to separate voice signals received from subscribers from datasignals received from subscribers, the splitter being further operableto communicate the separated voice and data signals; a voice processoroperable to receive the separated voice signals from the splitter,process the voice signals, and communicate the processed voice signalsfor routing within the switching system; and a digital subscriber line(xDSL) processor operable to receive the separated data signals from thesplitter, process the data signals, and communicate the processed datasignals for routing within the switching system.
 22. The switchingsystem of claim 16, wherein the switching system is further operable toselectively communicate available voice signals before available datasignals, according to their relative priorities.
 23. The switchingsystem of claim 16, wherein: the switching system further comprises aninterface; the interface is operable to receive remote voice signals andremote data signals from second switching system at the customerpremises; the interface is operable to receive local voice signals andlocal data signals from the switch; the interface is further operable toselectively communicate the available signal having the highestpriority; remote voice signals have the highest priority; local voicesignals have the second highest priority; and data signals have thethird highest priority.
 24. The switching system of claim 23, whereinremote data signals have the third highest priority and local datasignals have the fourth highest priority.
 25. The switching system ofclaim 16, further comprising an interface for coupling to one or moreother switching systems at the customer premises in a stackableconfiguration using one or more stack links, such that the switchingsystems are operable to function as a single logical unit incommunicating information associated with the subscribers.
 26. A methodof communicating voice and data information at a customer premisesassociated with one or more subscribers, comprising: communicatingdigital subscriber line (xDSL) signals between a switching system andsubscribers using a plurality of subscriber line ports of the switchingsystem, the xDSL signals comprising data signals and plain old telephoneservice (POTS) voice signals; communicating data signals and packetizedvoice signals between the switching system and a central office (CO)using a logical port of the switching system; converting between thePOTS voice signals of the subscriber line ports and the packetized voicesignals of the logical port for communication of voice signals betweensubscribers and the CO; and communicating data signals between theswitching system and a server complex using a local area network (LAN)port of the switching system to provide one or more data serviceaccessible to some or all subscribers.
 27. The method of claim 26,wherein the server complex comprises one or more servers selected fromthe group consisting of: a subscriber request server; a game server; avideo on demand (VOD) server; and a webcam server.
 28. The method ofclaim 26, wherein the logical port comprises one or more physical portseach coupled to a corresponding physical communications link between theswitching system and the CO.
 29. The method of claim 26, wherein eachlink comprises a wide area network (WAN) link supporting a protocolselected from the group consisting of: Asynchronous Transfer Mode (ATM);Internet Protocol (IP); and Frame Relay (FR).
 30. The method of claim26, wherein the xDSL signals comprise at least asymmetrical DSL (ADSL)signals.
 31. The method of claim 26, further comprising: separatingvoice signals received at the subscriber line ports from data signalsreceived at the subscriber line ports using a splitter of the switchingsystem; communicating the separated voice and data signals from thesplitter; receiving the separated voice signals from the splitter at avoice processor; using the voice processor to process the voice signals;communicating the processed voice signals for routing within theswitching system; receiving the separated data signals from the splitterat an xDSL processor; using the xDSL processor to process the datasignals; and communicating the processed data signals for routing withinthe switching system.
 32. The method of claim 26, further comprisingusing the switching system to provide connectivity to an Internetservice provider (ISP) for each subscriber line port.
 33. (Canceled) 34.The method of claim 33, further comprising communicating one or morerouting rules from a manager to the router for routing the data signals.35. The method of claim 34, wherein the routing rules reflect one ormore consideration selected from the group consisting of: trafficconsiderations; security considerations; and revenue considerations. 36.(Canceled)
 37. The method of claim 36, further comprising communicaterouting rules from a manager to the router for determination of thethird VC, wherein the routing rules reflect one or more considerationselected from the group consisting of: traffic considerations; securityconsiderations; and revenue considerations.
 38. The method of claim 36,further comprising: handling the voice signals and the data signalswithin the switch/router as asynchronous transfer mode (ATM) frames;using either ATM adaptation layer type-2 (AAL-2) or ATM adaptation layertype-1 (AAL-1) functionality at the switch to ensure that the voicesignals are switched to the first VC on which they were received; andusing ATM adaptation layer type-5 (AAL-5) functionality at the router toroute the data signals from the second VC to the third VC.
 39. Themethod of claim 36, further comprising implementing switching androuting within the switch/router using a single switch matrix. 40.(Canceled)
 41. A method of communicating voice and data information at acustomer premises associated with one or more subscribers, comprising:receiving voice signals at a switching system on a first virtual circuit(VC); using a switch of the switching system to route the voice signalsout of the switching system on the first VC; receiving data signals atthe switching system; communicating the data signals from the switch ona second VC for routing; receiving the data signals from the switch at arouter of the switching system; determining a third VC for the datasignals; and communicating the data signals from the router to theswitch on the third VC for communication out of the switching system onthe third VC. 42-44. (Canceled)
 45. The method of claim 44, wherein therouting rules reflect one or more consideration selected from the groupconsisting of: traffic considerations; security considerations; andrevenue considerations. 46-48. (Canceled)
 49. The method of claim 48,wherein remote data signals have the third highest priority and localdata signals have the fourth highest priority.
 50. (Canceled)